1. Field of the Invention
This invention relates to an electrical terminal with improved means for retaining the terminal in a terminal receiving passageway of a connector housing.
2. Description of the Prior Art
It is common in the electrical connector industry to require that electrical terminals have redundant retention means for retaining electrical terminals in the connector housings. The first or primary means of retaining the electrical terminals within the housing is to have a stamped out lance from the electrical terminal metal body which abuts a shoulder within the connector housing. The redundant or secondary retention means is typically profiled as a plastic movable member which can be moved into place over an edge or shoulder of the electrical terminal to lock the terminal in place in the connector housing. Some of these members are moved transversely of the axial direction, while some are defined as hinged flaps which are pivotly rotated into place. These flaps include plastic tabs which, when rotated, reside in the groove or gap within the terminal to cooperate with the terminal in order to retain the terminal in place.
In one prior method, as shown for example in U.S. Pat. No. 4,750,893, an electrical connector housing has a hinged flap which rotates or pivots into place in the housing. The electrical connector has an insulating housing and a plurality of pin terminals disposed in terminal receiving passageways within the housing. The housing includes an upper retention flap including a retention tab which, when in it's locked location, is positioned adjacent to an edge of the pin terminal to retain the pin terminal in the passageway. The flap has tabs which reside at an edge of the contact to prevent withdrawl thereof. If more than one row of contacts are presented, the two flaps on the outside of the two rows are used to retain the pin terminals in place.
One of the problems with the presently designed locking lances is that they have a tendency to buckle when an external pull-out force is exerted on the wire to which the electrical terminal was coupled. This often causes the terminals to become disconnected from the complementary electrical connector or device to which it was connected. This also resulted in the electrical terminal having a less than desirable pull-out force (i.e. the force required to pull the terminal out of housing). Another problem with the electrical terminals is that the locking lances include a continuous sheared edge which when pulled against the plastic shoulder of the connector housing can have a tendency to shear or cut away at the plastic shoulder in the connector housing and eventually dislodge the terminal from within the terminal receiving passageway.
The above mentioned problems can lead to one of more electrical terminals being pulled back from their fully inserted position. When a mating connector is installed, the associated contact could actually force the lose terminals out of the housing rather than making electrical contact with them, which would lead to an open connection. If the terminals are damaged or otherwise removed from the housing, installing new terminals into the assembly is quite difficult as the connectors and the electrical wires are intertwined within an extensive array of harnesses, which would require disassembling a large extent of the harness. It is therefore an object of this invention to provide an electrical terminal for use in a connector housing which has improved means for retaining the electrical terminal within the receiving passageway of a connector housing.
Another object of this invention is to provide a lance having an engaging surface which facilitates distributing the pull-out force of the lance over a larger area, so as to minimize the shearing action of the free end of the lance. Another object of this invention is to provide an electrical terminal comprising a lance having an embossed area which facilitates strengthening the lance, thereby increase the pull-out force of the electrical terminal.
Yet another object of this invention is to provide a lance having an engaging surface which is irregular in cross-section such that when a wire is pulled, the force, with which an edge of the lance engages the shoulder in the terminal receiving passageway, is distributed in a non-continuous way on the shoulder, thereby increasing the area over which the shearing force is exerted.